The present invention relates to a current generator, in particular for motor vehicles, which is composed of a liquid cooled generator and a liquid cooled internal combustion engine formed as a drive motor as well as a pump for the liquid coolant, which are arranged coaxially on a shaft.
Such a current generator is disclosed, for example, in the German patent document G 86 01 003. The water pump which is required for the cooling is arranged outside of the motor so that it is easily accessible for maintenance.
An air cooled current generator is disclosed in the U.S. Pat. No. 4,827,147. Current generators of this type have the advantage that the blower wheel does not need any maintenance. However, there are some disadvantages. In order to avoid two separate blower wheels, a single, double acting blower wheel is arranged between the motor and the generator. Fresh air is aspirated in two partial streams separately through the motor and through the generator and then jointly expelled. Thereby, the action of two separate blowers is obtained with one blower wheel.
Furthermore, the U.S. Pat. No. 4,486,668 describes a generator with a vacuum pump which is arranged between a driving V-belt pulley and the generator. The pump is easily accessible due to the belt drive. A coaxial arrangement of the motor and generator shaft is thereby avoided. The generator is not cooled with liquid. The pump does not operate for cooling.
The German document DE 35 34 507 A1 describes exclusively an internal combustion engine with a cooling water pump which has a magnet rotor. The pump is also easily accessible.
The known current generators have the same disadvantage that the armature shaft bearings or drive motor shaft bearings fail especially in narrow space conditions, which affects the operational safety.